Brake testing machine for motor vehicles



July'13, 1943. 1 H. WOCHNER 2,323,387

' BRAKE TESTING MACHINE FOR MOTOR VEHICLES Filed Nov. 8/1940 I 7Sheets-Sheet 1 FIE-l FIEi Zhwentor I July 13, 1943. q H; WOCHN ER2,323,887

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BRAKE TESTING MACHINE FOR MOTOR VEHICLES Filed Nov. 8., 1940 7Sheets-Sheet 3 me I v imventor M G ttotneu Jul "13, 1943.

H. 'WOCHNER Filed Nov. 8,- 194g FIE E FIE-ll 7 Sheets-Sheet 4 WWnventor' 94wzymwg a ttofn g July 13, 1943. H. WOCHNER 2,323,837

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BRAKE TESTING MACHINE MOTOR VEHICLES Filed Nov. 8, 1940 7 Sheets-Sheet 6Patented July 13, 1943 BRAKE TESTING MACHINE FOR MOTOR VEHICLES HenryWochner, Rock Island, Ill.

Application November 8, 1940, Serial No. 364,863

7 Claims. 73-51) My invention has reference to a brake testing apparatusfor motor vehicles, and aims to increase the efliciency and simplicityof machines of that type which are set forth in Letters Patent of theUnited States No. 2,171,283, issued'to myself Aug. 29, 1939. As in saidformer patent, means for transmitting the force exerted by setting thebrakes is of a mechanical character, arranged to show the relativebraking capacity of either the front or rear pair of wheels,independently of the other pair, and provided further with hydraulicmeans for indicating the total combined force of both pairs of wheels.

Instruments of the kind mentioned are frequently positioned in a safetytesting lane or station, along with other devices for determining thefaults of automobiles, and as it usually happens that a number of carsare in line for making the tests, it is to be desired that-the operationbe completed as expeditiously as possible, so as to prevent congestionof the vehicles. The present invention is designed specially for use ofthis kind, with a minimum amount of delay in a line of cars desiringsimilar service. matter of practice, and in the making of regular testsof the braking conditions it has been found possible to drive as many asone hundred and thirty cars in a procession over the apparatus in anhours time, and take the necessary readings, showing the condition ofthe brakes. This is on an average of more than two cars to the minute,and sufiiciently speedy to keep an ordinary line of vehicles passingthrough a testing field on the move most of the time, without danger ofbeing greatly hindered.

To bringabout the desired ends, as mentioned above, the indicating meansis actuated automatically by running a car upon the machine and settingthe brakes. Independent indicating instruments are provided for eachpair of wheels, and a third one of a hydraulic type to show the totalpressure of all of the Wheels, the readings on the several dials beingretained, until such readings may be checked, following which theindicators are released, as pointed out herein. Means is provided fordoing this manually, with the indicators manually released, andadditional or coacting means whereby the releasing can be effectedautomatically by one of the wheels of the vehicle as it leaves themachine. It is usual to support the indicators, or gauges in a casing ortower at one side of the machine, and it is found to be desirable toprovide duplicate indicating devices in both the front and rear walls,so that the readings can be checked either by those in the vehicle thatis being tested or by those at one side of the same, and the presentinvention has been specially arranged for such a use, with additionalmeans for effecting the release thereof by the mechanism above referredto, and simultaneously with the release of the first named gauges.

Another feature of the invention consists in the provision of controlmeans for the hydraulic devices, to aid in regulating the pressure ofthe liquid in the system, and prevent any variations therein fromexpansion due to heat conditions, or contraction due to lowtemperatures, from being reflected in the gauges, so as to give a falsereading therein.

The particular construction, arrangement, and manner of operation of theinvention and its various parts, will more fully appear from thefollowing specification, reference being had to the accompanyingdrawings, disclosing a preferred embodiment of the invention, in which;

Fig. 1 is a plan view, showing a general layout of the invention.

Fig. 2 shows one of the equalizer springs and its mounting, with some ofthe parts in section.

Fig. 3 is an enlarged detail of one of the mechanisms by means of whichthe brake testing force is imparted to the indicating gauges, in planView.

Fig. 4 is a similar view, with some of the parts shown responding to thebraking force, some tube 93.

Fig. 12 is a cross-section on the line I2-l2 of Fig. 13 with projectingportions of the indicators and GI omitted.

Fig. 13 is a fragmentary vertical section of the tower 24, lookingtoward the front wall there- Fig. 14 is a plan view of the top of tower24, with the cap 25 removed. 1

Fig. 15 is a detail of the hydraulic gauge release devices, forreleasing all of the gauges simultaneously.

Fig. 16 is a detail of the trip mechanism, for Operation by one of thevehicle wheels.

Fig. 17 is a cross-section on the broken line |1| 1 of Fig. 16.

Fig. 18 shows the hydraulic control devices, in

detail, somewhat diagrammatic.

Fig. 19 is a detail of the control mechanism for the indicators 4.

Fig. 20 is a cross-section on the broken line 2020 of Fig. 1.

Fig. 21 is similar to Fig. 20, with the parts in exploded position.

Fig. 22 is an enlarged detail of the hydraulic motor 52.

Similar parts are indicated by corresponding reference charactersthroughout the several figures.

The invention embraces two pairs of tread plates A and B, and C and D,supported on ground plates as at E, with anti-friction rollers Fseparating the ground-plates and tread-plates. The last-named plates aresuited to receive the two pairs of wheels of a motor vehicle, as thesame is being brought to a stop by application of the brakes. The innerends of one pairv of treadplates are spaced from the other pair, thespaces being filled by dummy plates G, one of which is removed in Fig. 1to show some of the mechanical parts. The plates G are spaced from thetread-plates a sufficient distance to permit a limited movement of thetread-plates in a lengthwise direction, in response to the momentum of avehicle thereon.

The inner ends of the tread-plates A and B are united by a bar 20, theends of which are pivoted to connectors 2|, as at b, secured to thecorners of the tread-plates by welding or other suitable method. The bar20 is pivotally connected with one end of a slide-frame 3|, as at a.Fixed to the bar 20, on the inner side thereof is a. connector 22,pivoted to the outer end of which is a rod or bar 23, extending inwardlythrough an opening in the lower part of a tower 24, supported at oneside of the tracks, and provided with a cap plate 25. The purposethereof will be more fully described hereinafter.

The rocking movement of the bar 20 on its pivot will cause areciprocating movement of the rod 23 in one direction or the other,imparting the movement of such bar to the indicating devices,

as later pointed out.

The relative movements of the tread-plates A and B are controlled bymeans of a pair of equalizer units 21, spaced from each other and fixedto the upper face of the bar 20. Some of the equalizer parts contact attheir ends with abutments 28 formed by turning upwardly the ends ofplates 29, which are fixed at their inner ends to the ends of across-bar 30, rigidly secured to a slide-frame 3|. Said slide-frame ismovable longitudinally of itself on a ground-plate H, filling the spacebetween the wheel treads at a point midway their ends. At their otherends of the equalizer units are movable parts which contact abutments 32at the inner ends of the plates 29, or with set-screws held in threadedopenings therein as at 33.

Each of the cylinders 21 is threaded in its ends to receive similarlythreaded plugs 34, provided at their outer ends with tool-holds forturning the plugs inwardly or outwardly in the cylinders. The plugs arealso provided with openings 35 to receive the pins 36 of plungers 31,which bear against the ends of coiled springs 38, contained in saidcylinders, and exerting an outward force. By the movement of the plugs34 the tension of the springs can be varied, to suit the requirements ofthe equalizing operations. The ends of the pins 38 have a bearingagainst the abutments, but are free to move away therefrom if necessary,during the operation. The springs act in the manner of shock absorbers,or equalizers of force, and prevent irregular or erratic movement of theparts.

Having pivotal connections with the inner corners of the plates C and Dis an equalizer bar 40,

similar to the bar 20 in arrangement and opera- 7 tion, and having apivotal connection with the slide-plate 3|, near the end thereofopposite to the pivoting of the bar 20. Connected with the bar 40 is apair of equalizer units 21, similar to those above described, and havingsimilar pins 36 contacting abutments 42 on plates 43 fixed at theirinner ends to a cross-bar 44 fixed to the slide-plate 3|. The outer pins36 contact setscrews in abutments 45 on the other ends of the plates 43.The bar 40 is also provided at a point midway its ends with a connector46, to which is pivoted one end of a rod 41, extending into the lowerpart of the tower 24, for connection with indicating devices in saidtower. The slideframe 3| and cross-bars 30 and 44 comprise a rigid framemovable in one direction or the other in response to a correspondingaction of the equalizer bars 20 and 40. This movement of the slide-frameand associated parts, which is in a direction length-wise of themachine, is of a free floating character, with a minimum of resistanceor hindrance to the action thereof in response to the movement of thetread-plates, or any force applied thereto. It is unhampered by anyattachments such as were shown in the earlier device shown in saidformer patent, which had a somewhat similar system, including across-bar which was anchored pivotally to a baseplate l2. This equalizerbar, also numbered 3|, was cross-ways of the machine, and could rock onits pivot, but had no sliding action.

Upon a pair of wheels being run upon one of the pairs of tread-plates,and the brakes applied, in case the force exerted on each wheel is thesame, the relative positions of the plates will not change, but if theamount of force varies, one of each pair of tread-plates will be moved agreater distance than the other, as illustrated to an exaggerated degreein Fig. 4, in which the force is indicated as being applied to theplates C and D, in the direction shown by the arrow. This movement wouldbe effected by the rear pair of wheels of a vehicle, in being run uponthe plates, and the brakes set, stopping the vehicle. At the same timethe forward pair of wheels would be exerting a stopping force upon theplates A and B. The arrangement is such that the vehicle can be run uponthe plates in either direction, and the brakes tested.

As before mentioned, any movement of the bars 20 and 40 is imparted tothe slide-frame 3|, and pivoted to said plate at a central point is acrossarm 49, one end of which has a connection with the frame 5| of ahydraulic cylinder 52, supported on the cross-plate H. The cylinder isprovided with a piston, (not shown) and rod 54 therefor, which rod isconnected with the frame 5|, and is moved by the rocking action of thearm 49, to cause a compression in the cylinder 52. The compressed chargeis effective through a tube 55 witha casing or casings in the tower 24for operation of indicating devices associated therewith. Springs 58hold the frame normally in extended position, and aid in returning theplates beneath the vehicle wheels to their former positions as soon asthe vehicle stops.

Positioned on the plate H is a pair of triangular stops 56 and 51, onopposite sides of the pivot 50, with which stops the arm 49 is adaptedto come in contact, on its opposite edges. In a movement of theslide-frame 3| in the direction shown by the arrow in Fig. 4, one end ofthe arm is held by the stop 56, and the arm rocks upon the pivot 50,carrying the other end in the direction indicated, and causing thecylinder 52 to operate. If the movement of the plate 3| is in theopposite direction th arm 49 comes in contact with the stop 5i, and thearm 49 is again rocked as the movement continues, and with rotation onthe pivot in the same direction as before, so that the cylinder pistonis moved in the same direction again, compressing another charge of theliquid.

One of the faces of the tower 24 fronts in the direction of thetread-plates, and in the upper part thereof (Fig. 5) is a pair ofopenings in which is positioned dial frames 60 and El, supporting dials62 and 63, each of which is provided with a scale having graduatedmarkings, as indicated at '64. Said scales start at the top with zero,and increase in value in each direction to the bottom. Each of the dialsalso has an indicator arm 65, fixed on a shaft 66, supported centrallyof the dial. On the inside of the dial is secured to the shaft a gearpinion 61 (Figs. 9 and 10), in mesh with the teeth of a gear rack 68,slidable against one edge of a bed-plate 69, and held in place by acover plate 10 fixed to the bed-plate, as by screws H.

The mechanisms just described, and other parts which assist in theoperation of the indicators, are similar, except that those ofone of thedials are reversed in position from those of the other one, but the samenumbers are made use of in referring to both of said mechanisms.

The bed-plate 69 is channeled for the passage The bed-plate 69 is alsorecessed to accommodate I a lock-bar 16, provided at its upper end withratchet-teeth Ti, engageable with a series of similar teeth '58 on theedge of the bar 13, at its upper end. At its lower end the bar isprovided with ratchet-teeth 19, for engagement with similar teeth 89 onthe edge of the bar 73, at its lower end. The arrangement of the teethis such that as the bar 13 is moved upwardly the teeth '19 and 89 willinterlock, preventing a return movement of the bar 13 downwardly. In thesame manner, if said bar is moved downwardly the teeth I! and 18 engage,locking the bar from return movement upwardly, This operates to hold theindicator 65 in shifted position until the reading on the dial has beenchecked.

The ends of the bar iii are concealed by extensions 8| and 82 of theplate 59, the ends of said extensions being turned inwardly to formstops for the ends of said bar. Pivoted to the outer face of the plate10, as at h, is a plate 85, from which a pin 86 is projected inwardlyinto the space between the bars 13 and i6, and upon the plate beingrocked upon its pivot the pin 86 is instrumental in forcing the bar 16away from the bar 13, to disengage one or other of the ratchet-toothmechanisms, in case they are engaged. The bar 76 is held in yieldableengagement with the bar 3 by means of a coiled spring 83 in a recess ina boss 84 on the plate 69. The rocking of the plate 85 is accomplishedby means of an arm 87, with which is connected a rod or wire 88, foroperation from below, as hereinafter described. The arm 81 is heldnormally in elevated position by a coiled spring 89 (Fig. 13), connectedwith said arm at its lower end, and at its upper end to a fixture in thetower casing.

The indicators 65 are actuated by the following means: The lower arm 14is perforated to receive the upper end of a rod 9il, threaded at itsupper end, and provided with a nut 9| above the arm, and a nut 92 belowthe same, with possibilities of adjustment of the positions of saidnuts, to hold the rod at a higher or lower point, as desired. The lowerend of the rod is held telescopically in the end of a tubular rod 93,the threaded part of the rod 90 being also provided with a turn nut 94,with which the upper nd of the rod 93 contacts. (Fig. 9.) The rods 90and 93 are held yieldably in telescoped relation by a spring 95,connected at its upper end with the rod 90, and at its lower end to apin 96 in the rod 93. In the lower end of the rod 93 is heldtelescopically a rod 91, (Fig. 8) the lower end of which is pivoted tothe long end of a bell-crank lever 98, pivoted in supports 99 on theplate IG J. Connected with the short end of said lever is the end of therod 23, leading from the equalizer bar 20, and a similar mechanism isprovided in the lower end of the tower 24 for the rod 4? from the bar49, with similar connections to the indicator devices at 6!, and notseparately shown herein. Upon a movement of the rod 23 the lever 98 isrocked, causing an upward or downward movement of the rod 93, in onedirection or the other, with a corresponding movement of the indicatingarm on the dial associated therewith.

Fixed t0 the lower end of the rod 93 is an arm Mil, having an angularend portion for the passage of the rod 91, the downward movement of saidrod being arrested by a nut 102 on said rod. A coiled spring I93 isinterposed between the angle of the arm IBI and a fixture I04 at thelowor end of the rod, which holes the angle yieldably in contact withthe nut I82. In case the long end of the lever 98 is moved downwardlythe rod 93 and rack 68 are moved in the same direction, causing theforce of the movement to be recorded on the gauge. If the arm 98 isrocked upwardly the rod 93 and rack 68 move in the same direction,recording the movement on the opposite side of the dial. In thefirst-named movement, as soon as the indicator hand is set the treadplates return to neutral position, without disturbing the position ofthe indicator. This is by reason of the teeth at the upper end of thebar 13 being engaged, and the bar locked in position. The rod 91 thenmoves upwardly in dependently of the rod 93, which is returned to itsoriginal position upon the release of the bar 13. The return of thetread-plates to neutral position is impelled by the force of the liquidin the hydraulic system, aided by the force of the springs 58 of thehydraulic cylinder.

In case the rocking movement of the arm 98 is upwardly, the rack 68 andbar 13 are moved upwardly by the rod 93, actuating the indicator hand inthe opposite direction, and causing the teeth at the lower end of thebar to engage with the teeth 79. As the parts come to a rest thetread-plates return to neutral again, the tubular part 93 of the rodmoving downwardly, as indicated in Fig. 11, with the bar still locked,and the reading on the gauge retained. Upon the release of the bar 73the rack and bar return to a neutral location, as shown in Fig. 9.

In using the gauges 6| and 62, in the upper part of the tower, one ofsaid gauges indicates the relative braking pressure of the front pair ofwheels, and the other one the relative pressure of the rear pair, inpositions corresponding with the positions in which the wheels stand onthe tread-plates, and depending upon the direction in which the vehicleis heading. The operation of the apparatus is of a reversible character,so that the car can be driven on from either direction. If the pointeron the gauge moves in the same direction as the vehicle, it shows thatthe wheel nearest the tower is showing greater stress than that of theopposite wheel on the same axle, and corrections can be madeaccordingly. Should the indicator move in the opposite direction, ortowards the rear of the vehicle, it shows that the wheel farthest fromthe tower is exerting the greater amount of force.

The reading indicates how much the braking effort of one pair of wheelsexceeds that of the other pair, and if the force is equal there is ofcourse no movement of the indicator.

As shown in Fig. 13, each of the indicator mechanisms is provided with arelease rod 88, and the two rods are united at their lower ends by across-rod 88a, from which a pin I08 projects outwardly through a slotI07 in the wall of the tower 2 and is provided on the outside of thecasing with a knob I68. By pushing said knob downwardly the bars I3 aresimultaneously released, and the indicators return to neutral position,ready for another test.

It has been found to be desirable to provide both faces of the towerwith indicating devices, so that identical readings can be hadsimultaneously from opposite sides thereof. An arrangement of this kindis shown in Fig. 14, wherein additional frames III] are secured atopenings in the opposite side of the tower, which arealso provided withdials and indicating pointers, not shown. These pointers, however, aresecured to the ends of the shafts 85, and turn therewith, and theoperation of such indicators is controlled by the actions of saidshafts, and corresponds with that of the indicators first described.Upon the release of the mechanism before pointed out, the returnmovement of the shafts 66 is imparted to the indicators in the frames atIII], so that no additional devices for locking and releasing the sameare required.

In order to make it possible to determine the total number of pounds ofbraking efiort, an additional indicating apparatus of a hydrauliccharacter is provided. This is also of a dual type, with casings ordrums I I I installed at openings in the front and rear walls of thetower 24, at a point a little lower than the other gauges. (Fig. 13.) Asshown in Figs. 5 and 7 each of said frames contains a dial II2, withmarkings of I I3 progressing from zero to any desired number, andindicating a pressure of one thousand pounds, and multiples thereof.Each indicator is fitted with a pointer IM, fixed on a shaft I I5, whichis under the control of devices in the casing III, of a common type, foruse by hydraulic pressure, one such arrangement being shown in Fig. 19.In said figure the casing I II is indicated, with one of its sidesremoved, and at the lower part of said casing is a pipe II Ia, for thepassage of the hydraulic element upwardly into the casing. Connectedwith said pipe is a flat coil II II), which tends to straighten out fromthe force within, and rock an arm IIIc pivoted on a support la. The armis also connected with a sector gear rack III 11, the teeth of which arein mesh with those of a pinion IIIe on the shaft I I5, from which theindicator H4 gets its movement. A spring plate II Ih is fixed at one endto a support IIIy' above the pipe IIIa, and exerts a frictional forceagainst a disk IIIm at the pivot point of the gear sector. As the gearsector is rocked downwardly it is held in its shifted position by theplate IIIh, until released by the pin I I1, engaging the plate I I Ih ata slight angle therewith, and moving it away from the disk. Foroperating purposes the casings III are provided with feed casings IIB,attached to the casings III and communicating therewith, and connectedby tubes 5541 with the main tube 55, leading from the cylinder 52. Bythe action of said cylinder the force of the fluid in the system isimparted in both casings III simultaneously, and also coincidently withthe operation of the mechanical gauges before described. The operationof the hydraulic liquid is under the control of other mechanism, whichwill be pointed out later.

Each of the casings III is provided with a release means, such as a pinIII extending into the same, and by the action of which the force can bereleased, in connection with the internal devices above referred to.This will permit the indicator hands I I4 to return to normal position,as in Fig. 7. A special mechanism for the simultaneous operation of saidrelease pins is provided, as follows: Secured at its ends in the endplates of the tower 24 is a supporting bar H8, in the middle part ofwhich is a flattened arch II9, upon which is pivoted an arm I20, toswing horizontally. One end of said arm is connected with one of thepins M1 by a rod I2I, bent at its end, and perforated to receive the endof the pin, which is threaded and fitted on opposite sides of the rodend with nuts I23 and I24 (Fig. 12). The other end of the arm I20 issimilarly connected with the other pin I". By means of the threadedconnections relative adjustments of the pins and rods can be made.

The first-named rod I2I is projected into an arm I25, with a downwardlyturned end I26, (Figs. 14 and 15) and fixed to the lower side of the barI I8 is an angle-plate I21, to the end of which is pivoted at f a framepiece I29, to the upper end of which is fixed a cross-head I30,contacting the inner end of the end piece I25. Fixed to the lower end ofthe piece I29 is a plate I3I, turned with its fiat side upwardly, andpro jecting beneath the cross-rod 88a. When the cross-rod is moveddownwardly by means of the knob I08 the piece I29 is rocked, with thecrosshead I30 moving the arm I25 and rod I2I in a direction to releasethe force in one of the casings I I I. At the same time the arm I29 isrocked on its pivot, causing the other rod I2I to actuate the releasepin II! to which it is attached, releasing the pressure in the othercasing. The hydraulic casings are thus both relieved at the same time,and coincidentally with the return of the other gauges to neutral.

Means is also provided for the instant and coincident release of all ofthe indicators, by the operation of one of the wheels of a vehicle beingtested, which consists of a shaft I33, rockingly supported in a bearingI34 on the plate I00 forming a lateral extension of the plate H (Figs.16 and 17) and connected at one end with a trip plate I35, having avertically disposed blade I36 projected upwardly through a slot I31 inone of the dummy plates G over which the wheels of a car travel, so thatthe blade will protrude a little above the plate. Fixed to the other endof the shaft I33 is an arm I38, with which is connected a cord or wireI39, extending upwardly in the tower 24 to an attachment with thecrossrod 88a. As a car is driven from the machine one of the Wheelspasses over the blade I36, forcing it downwardly, and rocking the armI38, to release all of the gauges simultaneously, similarly to theoperation of the knob I08.

It will be obvious that it is a simple matter to drive a vehicle uponthe tread-plates, set the brakes, check up on the indicators, and driveoff again, setting the machine for the next test.

In the use of the hydraulic system for operating the gauges I I2, thereis danger of the action of the liquid being interfered with by hightemperatures, causing an expansion of th liquid, which will be reflectedon the indicating devices, or of low temperatures, tending to cause avacuum in the recording apparatus. In either case there is a possibilityof the indicator hand being moved to one side or the other, sufficientlyto cause a false reading when the test is being made. To prevent this anextra supply of the hydraulic liquid is stored in a small tank I 46,supported near the upper end of the tower 24, at one side thereof. (SeeFig. 18.) Tubes llI connect said tank with the feed casings H6, thelower ends of said tubes being provided with check valves I42, which areinactive at such times as the apparatus is idle, but which closeautomatically when pressure is exerted by the cylinder 52. The tank I ispartially filled with the liquid under normal pressure, which tends tokeep the system operating under uniform force at all times, withoutinterfering therewith when its help is not required. If there is dangerof a vacuum in the indicating mechanism the liquid in the tank makes upthe deficiency.

It will be obvious that changes can be made in the form and arrangementof the various parts of the invention without departing from the purposeand scope thereof, as set forth herein.

What I claim, and desire to secure, is:

1. In a brake testing machine, a casing, a gauge mounted thereinprovided with a rotatable shaft and pointer thereon, gearing in saidcasing operatively connected with said shaft, including a slidable barhaving ratchet teeth thereon at both ends, a lock-bar having teeth atboth ends engageable with said ratchet teeth, to lock the slidable barat either end of its movement, a release lever for said lock bar, meansfor imparting a reciprocating movement to said slidable bar, and meansfor actuating said release lever.

2. In a brake testing machine, a casing, a gauge mounted thereinprovided with a rotatable shaft and pointer thereon, gearing in saidcasing operatively connected with said shaft, including a slidable barhaving ratchet teeth thereon, a lock-bar having teeth engageable withsaid ratchet teeth to lock the slidable bar at the end of its movement,a release for said lock bar, and means for operating the same, a rodconnecting said slidable bar in a downward direction, and formed oftelescoping parts, and a spring uniting said telescoping parts, andpermitting the movement of one ofv said parts independently of theother.

3. In a brake testing machine embracing movable tread-plates to receivethe wheels of a motor vehicle, and equalizer bars connecting the same inpairs, an indicating device operatively connected with one of said bars,including a connecting rod provided at both of its ends with telescopicparts, springs for yieldable connection of such parts, mechanism foroperation of the indicating device, including means for locking the samein indicating position, operable by said rod, and means for the releaseof said locking means.

4. In a brake testing machine, a supporting frame, two pairs oftread-plates mounted on said frame for limited lengthwise movement, apair of equalizing bars connected with said pairs of plates at theirinner ends, one for each pair, a slide-frame on said supporting frame,operatively connected with said bars, a tower at the side of saidtread-plates, indicating devices in said tower, connections between saidindicating devices and said bars, to actuate said devices, a cross-armon said slide-frame, a hydraulic cylinder on said supporting frame,operatively connected with said cross-arm, hydraulic indicating devicesin said tower, and connections between said cylinder and the last-namedindicating devices to give movement thereto.

5. A brake testing machine, comprising a ground frame, two pairs oftread plates supported on said frame, for a limited lengthwise movement,and adapted for the support of the front and rear wheels of a motorvehicle, bars having a pivotal mounting above said ground-frame,connecting said pairs of tread-plates at the inner ends thereof, one foreach pair, a slide-frame on said ground frame, operatively connectedwith said bars, a tower at the side of said tread-plates, indicatingdevices in said tower, connections between the indicating devices andsaid bars, a cross-arm pivoted on said slide-frame, and means forlimiting the movement thereof mounted on the ground-frame, a hydrauliccylinder on said ground frame, in proximity to one end of saidcross-arm, and operatively connected therewith, hydraulic indicatingdevices in opposite sides of said tower, connections between saidlast-named indicating devices and said hydraulic cylinder, and means forreleasing the last-named indicating devices.

6. A brake testing machine, comprising a ground frame, two pairs oftread-plates mounted on said frame for limited movement lengthwise, andadapted to receive the front and rear wheels of a motor-Vehiclesimultaneously, equalizer bars connected with said pairs oftread-plates, a tower in proximity to said tread-plates, having acentral space of rectangular form in cross-section, shafts in said spacetransversely thereof, indicating devices at the ends of said shafts inopposite walls of the tower, including indicating pointers connectedwith said shafts, gearing connected with each of said shafts at one endthereof, means for actuating said gearing to cause a simultaneous actionof the indicators, means for locking said indicators at the end of theindicating movements, means for simultaneously releasing saidindicators, and connections between said gearing actuating means andsaid equalizer bars, to impart the movement of the bars thereto.

7. In a brake-testing machine, a groundframe, two pairs of tread-platessupported on said ground-frame for a limited movement lengthwise, andadapted for the support of the connected with said cross-arm, a toweradjacent to said ground-frame, gauge devices in said tower, including anindicating arm and shaft therefor and a scale for use with saidindicating arm, a hydraulic apparatus in said tower connected with saidshaft to operate the same and said indicating arm, and connectionsbetween said last-named apparatus and said hydraulic cylinder, toreceive power therefrom, for imparting to the gauge devices the relativebraking stress of wheels supported on the tread-plates.

HENRY WOCHNER.

